Growth and reproduction of Amygdalus tangutica (Batal.) Korsh. population in arid valley sites along the Minjiang River

Amygdalus tangutica (Batal.) Korsh. is a native shrub species with high ecological and economic value found in the arid valley area of Southwest China. Here, we surveyed arid valley sites along the Minjiang River from the Maoxian to Songpan counties. We recorded 47 survey points where A. tangutica was abundant. Among these points, five plots were established to investigate community structure. Six shrub quadrats and 12 herb quadrats were investigated in each plot. To examine vegetative and reproductive characteristics, four sites were selected, with 20 shrubs randomly selected at each site. Variables of shrub and ramet growth (e.g., age, height, basal diameter, canopy area, branch number) and reproduction (e.g., number of fruits and fresh weight of fruit) were determined. Results showed that:(1) A. tangutica formed communities with high species richness (43-55 species/24 m²) and was widely distributed in the arid valley sites along the Minjiang River. (2) An average of 8.83 ±2.25 fruits were found on each shrub. (3) An average of 7.38 ±0.46 sprouts were found on each shrub, with 25.68% of sprouts within the age range of 5-10 years. The ratio of fruit weight to vegetative organ weight was only (0.69 ±0.16)%, indicating weak sexual reproduction capacity. (4) Growth and fruiting parameters were significantly correlated, and fruit number was significantly affected by age and height. Our results suggest that A. tangutica has adapted to the arid valley environment by producing sprouts. However, resource conservation is urgently needed.